The prior art discloses a wide variety of machines adapted for packaging, wrapping and labeling various types of products. For example, U.S. Pat. Nos. 3,213,591 and 3,497,412, assigned to the assignee of the present application, disclose packaging, wrapping and labeling devices peculiarly adapted to the packing, wrapping and labeling of paper products, such as reams of bond paper. To facilitate the shipping and storage of products wrapped and labeled by devices such as those disclosed in the foregoing patents, considerable attention has been directed over the years to ensuring that the wrapping material for the individual products, usually heavy paper, is uniformly applied to the products to produce a wrapped product which is attractive in exterior appearance and uniform in exterior dimensions. Similarly, the label applying devices known in the prior art have been designed to ensure that labels are consistently applied to all packages passing through the labeling apparatus and also consistently applied to a preselected location on the package.
While prior art devices have achieved a great measure of success, instances have been noted where packages leaving known types of wrapping machines are defective due to the presence of loose end flaps on the wrapping paper, loose girth wraps or loose girth seams, pulled out end tucks, sheets of the ream of paper extending through the girth seam of the package, and related problems. Similarly, the label applying apparatus known in the prior art has shown a tendency on occasion to apply labels in an improper location on the package or, in some instances, to fail to apply any label at all. The above mentioned defects in the package wrap and in the placement or non-placement of the package label can lead to later difficulties in handling, packing and storing the wrapped products and in identifying their contents.
Thus, it is apparent that a need exists for an apparatus which will inspect a previously wrapped package to determine whether the package is defective for any of the above or additional reasons and to reject any defective packages from the conveying apparatus on which they are moving. Likewise, a need is evident for means which will detect the misplacement or non-placement of a package label and reject a defective package accordingly.